Seat, especially an aeroplane seat

ABSTRACT

The invention relates to a seat, preferably an aeroplane seat, comprising a seat base ( 12 ) which can be positioned on the floor and seat components which are provided for each seat and are arranged on the seat base ( 12 ), such as a seat back ( 1 ) and a seating element ( 2 ) comprising a front region ( 3 ) and a rear region ( 4 ), said rear region being located at the point where the seating element joins the seat back ( 1 ). According to the invention, said seat back can be displaced from an upright position to an inclined position and vice versa, simultaneously adjusting the inclination of the seating element ( 2 ), the front region ( 3 ) of the seating element ( 2 ) essentially maintaining its height above the floor and the rear region ( 4 ) sinking as the seat back ( 1 ) increasingly inclines. The seat back ( 1 ) consists of at least one first part ( 5 ) and one second part ( 6 ) which at least partially support each other with the adjacent surfaces thereof and can be displaced in relation to each other during the adjustment of the inclination of the seat back ( 1 ) such that the inclination of the seating element ( 2 ) is automatically adjusted. As a result, the rear region of the seating element significantly sinks as soon as the seat back is slightly inclined towards the rear, the front region of the seating element maintaining the same position.

The invention relates to a seat, preferably a passenger seat, especially an aeroplane seat, with a seat frame which can be positioned on a floor, and with seat components which for each respective seat are positioned on the seat frame, such as a seat back and a seat part with a front and a back area at the location of the transition to the seat back which can be moved from an upright position into an inclined position and vice versa, and in the process at the same time adjusts the seat part in its incline, the front area of the seat part essentially maintaining its height relative to the floor, and the back area being lowered with increasing inclination of the seat back.

WO 00/29249 discloses a vehicle seat, with a seat part and a seat back part which is held on the seat frame by means of side cheeks and which can be moved relative to it by means of an actuating drive, the actuating drive with body position detectors being control-connected for moving the respective seat part or seat back part forward or backward to the body position assumed by the seat occupant or according to the body movement of the seat occupant. In the known approach the seat part and the seat back part are adjustably guided in a type of restricted guidance, the seat part and the seat back part being pivotally connected to one another by way of an articulated axis and the seat part and the seat back part each being guided with a distance to the articulated axis and being rotatable around their guide axes. The indicated body position detector is designed as a distance measuring means, but can also be a pressure sensor or pressure switch which allows adjustment motion of the seat controlled by the operator.

The known seat design is ergonomically perfected and allows a plurality of adjustment possibilities, in which the seat part and seat back part can also be controlled and adjusted separately from one another. Based on the indicated sensor technology by way of the body position detectors, the associated control cost for the seat is correspondingly high so that the known seat design is expensive and complex to produce and as a result of the plurality of components and the indicated control, failures in operation cannot be avoided. Furthermore the known seat is relatively heavy; this would indicate that its use in the aircraft domain is not altogether practical, so that the pertinent seats are used preferably in the first class section of aircraft.

U.S. Pat. No. 5,636,898 and EP-A-1 057 725 disclose comparable seat designs in which the front area of the seat part is raised automatically with the tilt adjustment of the seat back into a backward position, by which the tilt adjustment for the seat part itself inevitably arises. Since the raising of the thigh of the seat occupant is associated with the raising of the front edge of the seat part, overall the legs are moved away from the respective floor of the vehicle; this is perceived as not always pleasant from the ergonomic standpoint of the operator.

Conversely, DE-C-42 22 222 and U.S. Pat. No. 5,133,587 have already proposed essentially fixing the front area of the seat part by way of a type of rotary or swivel function in height relative to the floor and swivelling the seat back together with the seat part which are designed as a common shell for a change in the position of the seat components relative to the front edge of the seat part. In the pertinent designs generally a distinct tilt adjustment of the seat back in addition to its lowering into the backward position is necessary in order to be able to lower the seat part in an ergonomically favorable manner in the back area. For a correspondingly comfortable adjustment process the seat back therefore has to be inclined far back; this entails loss of comfort for the individual in the row of seats behind.

On the basis of this state of the art, the object of the invention is to improve the known seat designs such that with low mechanical effort and using a minimum of space, comfortable, ergonomically favorable matching of the seat to the concerns of the respective seat occupant is achieved. Furthermore, the design is to be economically implemented and to require little structural weight. This object is attained by a seat with the features of claim 1 in its entirety.

In that, as specified in the characterizing part of claim 1, the seat back consists of at least one first back part and another back part which are at least partially in contact with one another with their facing surfaces and which can be adjusted relative to one another when the inclination of the seat back is adjusted such that tilt adjustment for the seat part takes place automatically, when the seat back is tilted back slightly a distinct lowering of the back area of the seat part is obtained, the forward area of the seat part maintaining its position. Consequently, when the seat back is leaned slightly backward, compared to the known approaches the opening angle for the seat part is distinctly increased so that a high degree of comfort is achieved for the seat with the associated seat frame in a reduced installation space. The relative motion between the first and the other back part, which ultimately automatically causes the lowering of the seat part in the back area, is dictated by a structurally simple control design which is technically extremely reliable in operation, which requires few structural components, and still provides a high degree of comfort. As a result of the few required components the seat can be largely built to be lightweight; this makes its use especially advantageous in aircraft. In particular the use of the seat in the so-called economy section of aircraft is intended. But it is also quite possible to use the seat for seating in movie theaters or the like to enhance comfort.

In one preferred embodiment of the seat as claimed in the invention the one back part is provided with seat upholstery and the other back part designed as a frame or back shell holds the first back part in its back area. By designing the other back part as a frame or back shell, on the one hand the forces applied to one back part can be deflected at the same time, especially in the event of a crash, and otherwise the other back part can be made lightweight provided that one back part accommodates the forces which are applied largely structurally.

In another preferred embodiment of the seat one back part is connected to the seat part, the seat part with a definable angle being coupled to one back part. In the pertinent configuration there is on the one hand the possibility of connecting the back part and the seat part to one another in one piece, it then being surprising that in spite of the rigid connection, when the other back part is reset and consequently when the seat back is inclined, the seat part at the same time is lowered in an ergonomically favorable manner in the back area. If one back part is connected to the seat part by way of at least one swivelling axis, there is moreover the possibility of further increasing the opening angle previously referred to when resetting the incline and in addition the variance of adjustment possibilities between one back part and the assigned seat part is higher.

In another preferred embodiment of the seat as claimed in the invention the back parts are coupled to one another by way of a coupling mechanism, in particular by way of a longitudinal guide such that in the upright position the top edge of the back of one back part ends in the area of the top edge of the other back part and that in a suitable position conversely the top edge of the back of one back part is lowered together with the back area of the seat part. This yields on the one hand an elegant structure of the seat and by the coupling mechanism designed as a longitudinal guide the relative adjustment of the back parts to one another can be undertaken reliably and with precision using few components. Preferably provision is made such that the swivelling axis for the other back part in the upright position has essentially the same height as the back area of the seat part and that in the inclined position the swivelling axis runs above the back area of the seat part.

If in another preferred embodiment of the seat as claimed in the invention one back part with the assigned seat part is designed as a base frame which provided with net covering bears the seat upholstery, by way of the indicated net covering effective application of force to the seat and consequently to the seat frame can be achieved, especially in the case of a crash, it being ensured that the base frame does not collapse unintentionally.

In another preferred embodiment of the seat as claimed in the invention, the base frame as part of the coupling mechanism bears guide parts which fit partially into guides of the respectively assignable armrest and/or into parts of the seat frame. As a result the indicated guides with their imaginary extensions delimit a type of circular arc with a center point which is the imaginary pivot for the motion of the base frame relative to the other back part. The swivelling motion of the seat part and the back part then essentially takes place around the imaginary pivot which has been obtained without the seat part necessarily being moved translationally in the longitudinal direction or the front edge of the seat part undergoing an ergonomically unfavorable lifting motion.

In another preferred embodiment of the seat as claimed in the invention, the other back part is provided with a folding table part on its rear, in the folded-up state of the table part on its locking means there being possible equalization of length between the table part and the other back part. In this way it is ensured that when the inclination of the seat back is adjusted, the table part is entrained and in each tilt adjustment position of the seat back the table part can be folded out and for the operator seated behind can be made accessible for his use.

In another preferred embodiment of the seat as claimed in the invention a plurality of seats arranged next to one another are mounted on a common seat frame.

Exemplary embodiments of the seat as claimed in the invention are detailed below with reference to the drawings. The figures are schematic and not to scale.

FIG. 1 presents in a view two seats as claimed in the invention located next to one another, on the right seat as seen in the line of sight there being two different adjustment positions;

FIGS. 2A, 2B presents in a side view two different adjustment positions of the seat;

FIG. 3 presents in the manner of an exploded view with a partial elevation the essential components of the seat;

FIGS. 4A, 4B presents in an oblique view from the rear the seat in two different adjustment positions with the table part folded up.

FIG. 1 presents an embodiment of the seat as claimed in the invention with a seat back 1 and a seat part 2 which has a front area 3, and a back area 4 at the location of the transition to the seat back 1. The seat back 1 consists of a first back part 5 and another back part 6 which with their facing surfaces are at least partially in contact with one another and are adjustable relative to one another. The adjustment motion of the seat back 1, which is indicated in FIG. 1 by the arrow, into one of its tilt positions causes relative displacement of the first back part 5 relative to the other back part 6, and coupled to it a change of the tilt adjustment for the seat part 2.

FIGS. 2A and 2B present the sequence of motions which accompany the change of the setting of the seat back 1. In the base position of the seat shown in FIG. 2B the seat back 1 is in the almost upright position and the seat part 2 is in the almost horizontal position. To adjust the seat to a comfortable position it is desirable to incline the seat back 1 to the rear and at the same time to lower the back area 4 of the seat part 2 without in the process lifting the front area 3 of the seat part 2 in order not to exert increased surface pressure on the areas of the lower leg near the hollow of the knee; this for example could cause restricted circulation and thus represents a limitation of comfort. The described manner of adjustment is achieved in that when the seat back 1 is swivelled backward one back part 5 which bears the upholstery 7 slides down on the other back part 6 and in the process changes the incline of the seat part 2 by way of the connection in the form of an axis 8 such that the backward area 4 of the seat part 2 is lowered. As a result the height of the front area 3 of the seat part 2 remains essentially unchanged. In the described process the top edge of the back of the back part 9 is lowered relative to the top edge of the back of the other back part 10 and the location of the axis 8 relative to the coupling point 11 is also displaced to the corresponding degree. Tilt adjustment takes place around this coupling point 11 which also forms the swivelling axis for the entire seat back 1. The movement position with the lowered seat part 2 is shown in FIG. 2A.

FIG. 3 presents the seat which a seat frame 12 which can be positioned on a floor with two cross members 25 extending on its top end. To either side of each seat an armrest 13 can be attached to the cross members 25 in a manner which is not detailed; in its guides 14 which are designed as elongated recesses assignable guide parts 15 can be accommodated and are fixed on the base frame 16 of the seat. Depending on the selection of the length of the cross members 25 it is possible in this way to place not only one seat, but a plurality of seats next to one another in the transverse direction on one seat frame 12. This means not only saving money, but also saving weight per installed seat.

The base frame 16 is formed from the respective frame parts of one back part 5 and the seat part 2. In an integral configuration of the base frame 16 the respective frame parts are rigidly connected to one another. In another embodiment which is not shown, the base frame 16 is designed partially movable in itself by the frame part of the seat part 2 being pivotally connected to the frame part of one back part 5 by way of another swivelling axis (not shown) in its back area 4 or approximately in the middle. Since for the adjustment motion of the seat back 1 the guide parts 15 are movably held in the guides 14, the guides 14 have a shape which is adapted to the desired direction in which the adjustment motion runs, especially a straight slotted or curved slotted shape.

To release and lock the adjustment motion of the seat back 1 and the seat part 2 there is a locking means 24 which can be controlled by way of a control element 23 which is preferably integrated in the armrest 13. Control can take place mechanically, electrically or hydraulically. Preferably the locking means 24 allows continuous adjustment of the seat. But there can also be adjustment modes which allow adjustment of the seat automatically to certain defined or definable positions. In the area of its upper end part 18, the base frame 16 has other guide parts 19 by way of which it is connected to the other back part 6. For this purpose the guide parts 19 fit into the other guides 20 which are made as elongated recesses on the other back part 6.

The other back part 6 in FIG. 3 is designed as a back shell which holds one back part 5 in its back area. The other back part 6 can however also be designed as a stiff tube frame construction, with which a further weight savings can be achieved. The main function of the other back part 6 consists in forming a mechanical abutment and a guide for one back part 5 and in this way mechanically stabilizing the entire construction. By possible division of the supporting function between the first back part 5 and the other back part 6 the first back part 5 and the entire base frame 16 can be made as a lightweight structure.

With the described configuration the base frame 16 is overall a part of a coupling mechanism which movably connects the first back part 5 to the other back part 6 or to the armrest 13 by way of the guide parts 15 and the other guide parts 19. The base frame 16 is provided with a net covering 17 and bears the upholstery 7 of the seat. By suitable material selection in the net covering 17, for example in the form of a synthetic monofilament such as nylon, the net covering 17 can not only be made very lightweight, but due to the high tensile strength at the same time allows an increase in the torsional stiffness of the base frame 16. By suitable selection of the type of net covering 17 a three-dimensional shape of the net covering 17 can be achieved so that with ergonomic shaping of the seat by the corresponding contouring of the upholstery 7 further material savings are possible.

On the rear of the other back part 6 there is a folding table part 21, as can readily be seen from FIGS. 4A and 4B. The folding table part 21 is held by a locking means 22 in the folded-up state which is shown in FIGS. 4A, B. The locking means 22 in the adjustment motion of the seat approximately from the upright position (FIG. 4A) into an inclined position (FIG. 4B) of the seat back 1 allows equalization of the length between the folding table part 21 and the other back part 6. As a result a displacement motion of the folding table part 21 which proceeds simultaneously with the adjustment motion of the seat back 1 takes place relative to the locking means 22 which is located stationary on the other back part 6.

The described displacement motion occurs in the case of a separate coupling, i.e., one which takes place on different swivelling axes, of the other back part 6 and the folding table part 21. By joint coupling to the coupling point 11 the displacement motion can therefore be avoided. In any case coupling of the folding table part 21 takes place however such that the table part in the folded-down operating state always remains unaffected by the adjustment motion of the seat back 1.

The two longitudinal guides 14 in the area of the armrest 13 with their imaginary extensions in the direction of the seat frame 12 form an obtuse angle with one another. If a circle were to be drawn by approximation through the two guides 14, the middle point of this imaginary circle would be the pivot or center of gravity around which the base frame 16 is displaced by way of the guide parts 15 in the guides 14. Since in the pertinent “side to side rocking” the other guide parts 19 on the top end part of the base frame 18 slide in the other guides 20 of the other back part 6, the other back part 6 is necessarily entrained into the backward inclined position according to the arrow as shown in FIG. 3. After actuating the locking means 24 the pertinent motion is controlled exclusively by the weight of the seat occupant so that with few adjustment and control means tilt adjustment takes place with simultaneous lowering of the seat part bottom. In order to prevent the other back part 6 from unintentionally folding down from the first back part 5, the other guide parts 19 on the base frame 16 can be provided with fixing means, for example in the form of widened pegs (not shown) which counteract the disengagement from the guide part 19 with the assigned other guide 20.

The other back part 6 in the embodiment shown is built as a shell element which basically does not accommodate any forces. To further reduce the weight, instead of the indicated shell part the other back part 6 could also be designed as a frame or frame hoop in which the base frame 16 and consequently the first back part 5 can slide. If the locking means 24 is provided with the corresponding force means such as servo cylinders, by actuating the locking means 24 supported motion in the opposite direction can be implemented, in which the seat back 1 is reset into the upright position.

To ensure a harmonious sliding motion, at least the front cross member 25 of the respective seat frame 12 is designed as a slide roller and the seat part 2 on its bottom as seen in the line of sight to FIGS. 2A, B has a type of sliding block guide 26, in the front area 3 a concave component 27 passing into a convex component 28. This convex component 28 which is more sharply curved than the concave component 27 also results in reinforcement of the seat part 2 in this area so that with intensified application of force (crash case) by the seat occupant in the straight arrow as shown in FIG. 2 A the forces can be securely captured by way of the seat part 2. The concave component 27 of the sliding block guide 26 conversely ensures that more or less frictionless sliding motion of the front area 3 of the seat part 2 is possible, in its lowering motion as shown in FIG. 2A or in the return motion as shown in FIG. 2B.

As furthermore shown in FIGS. 2A and 2B, with a rigid configuration of the base frame 16 the angle between the first back part 5 and the seat part 2 is essentially constant (approximately 100 degrees) regardless of the respective tilt adjustment situation of the seat back 1. While the seat back 1 as shown in FIG. 2A in the direction of the curved arrow shown there is tilted backward, specifically around the coupling point 11, the first back part 5 within the other back part 6 is displaced in the direction of the longitudinal arrow shown in FIG. 2A. As a result the axis 8 is lowered from the base position shown in FIG. 2B down to under the coupling point 11 (cf. FIG. 2A). In the upright position on the other hand the axis 8 is then located above the coupling point 11. For the pertinent lowering motion the indicated angle between the first back part 5 and the seat part 2 remains essentially constant. Furthermore, it should be noted that with the pertinent tilt adjustment with simultaneous lowering of the back area 4 of the seat part 2 the front area 3 of the latter undergoes essentially no changes, in particular the seat part 12 in the front area does not execute any lifting motion. Rather the horizontal plane is maintained; this is represented in FIGS. 2A and 2B by the horizontal broken line 29. When the opening angle and the seat bottom angle are increased therefore the height under the hollows of the knees of a seat occupant remains the same so that in this way obstruction of blood circulation or the like cannot occur.

The basic seat construction is designed such that it can also be retrofitted for existing systems. Furthermore, by closing the guides 14, especially in the armrests 13, by suitable plastic closure pieces (not shown) the illustrated luxury seat can be converted back again into a conventional basic seat. 

1. Seat, preferably a passenger seat, especially an aeroplane seat, with a seat frame (12) which can be positioned on a floor, and with seat components which for each respective seat are located on the seat frame (12), such as a seat back (1) and a seat part (2) with a front area (3) and a back area (4) at the location of the transition to the seat back (1) which can be moved from an upright position into a inclined position and vice versa, and in the process adjusts the seat part (12) in its incline at the same time, the front area (3) of the seat part (2) essentially maintaining its height relative to the floor, and the back area (4) being lowered with increasing inclination of the seat back (1), characterized in that the seat back (1) consists of at least one first back part (5) and another back part (6) which are at least partially in contact with one another with their facing surfaces and which can be adjusted relative to one another when the inclination of the seat back (1) is adjusted such that tilt adjustment for the seat part (2) takes place automatically.
 2. The seat as claimed in claim 1, wherein the one back part (5) has seat upholstery (7) and wherein the other back part (6) designed as a frame or back shell holds the first back part (5) in its back area.
 3. The seat as claimed in claim 1, wherein one back part (5) is connected to the seat part (2) and wherein the seat part with a definable angle is coupled to one back part (5).
 4. The seat as claimed in claim 1, wherein the back parts (5, 6) are coupled to one another by way of a coupling mechanism, especially by way of a longitudinal guide such that in the upright position the top edge (9) of the back of one back part ends in the area of the top edge (10) of the other back part and wherein in an inclined position conversely the top edge (9) of the back of one back part is lowered together with the back area (4) of the seat part (2).
 5. The seat as claimed in claim 1, wherein the swivelling axis (8) for the other back part (6) in the upright position has essentially the same height as the back area (4) of the seat part (2) and wherein in the inclined position the swivelling axis (8) extends above the back area (4) of the seat part (4).
 6. The seat as claimed in claim 1, wherein one back part (5) is connected integrally or by way of at least one other swivelling axis to the seat part (2) and with the latter forms a base frame (16) which provided with a net covering (17) bears the seat upholstery (7).
 7. The seat as claimed in claim 6, wherein the base frame (16) as part of the coupling means bears guide parts (15) which fit partially into guides (14) of the respective assignable arm rest (13) and/or into parts of the seat frame (12).
 8. The seat as claimed in claim 7, wherein the indicated guides (14) with their imaginary extensions border a type of circular arc with a center point which is the imaginary pivot for the motion of the base frame (16) relative to the other back part (6).
 9. The seat as claimed in claim 1, wherein the other back part (6) is provided with a folding table part (21) on its back and wherein in the folded-up state of the table part (21) on its locking means (22) equalization of length between the table part (21) and the other back part (6) being possible.
 10. The seat as claimed in claim 1, wherein a plurality of seats arranged next to one another are mounted on a common seat frame (12). 